cross bikes have a slightly longer wheelbase to allow for bigger tyres. I don't think it's too hard for manufacturers to make disc frame and forks for 23/25mm tyres. You'd get the same geometry with better stopping power of the discs.

I really hate that grinding noise my rim brakes make on rainy days. "guh, that doesn't sound healthy".
Now if you'll excuse me, I'm going to wipe down my rims with some rubbing alcohol and clean my brake pads while I'm at it since I got caught in the rain yesterday.